Bi-directional communication system, display apparatus, base apparatus and bi-directional communication method

ABSTRACT

A bi-directional communication system comprising abase apparatus and a display apparatus. The display apparatus is a portable liquid crystal display for viewing video programs and browsing the internet. The base apparatus contains a television tuner for receiving broadcast signals and wirelessly transmits programming to the display apparatus. An infrared remote control device connected to the base apparatus is used to control various external input devices (e.g., a VCR or DVD player). Control menus for the base apparatus and the external input device can be displayed on the display apparatus. The display apparatus contains a touch screen, so that a user can select operational commands for controlling the base apparatus and external input devices. The display apparatus wirelessly transmits selected operational commands to the base apparatus, which then retransmits the commands to the appropriate external input device using the infrared remote control device.

This is a continuation of application Ser. No. 09/906,922 filed Jul. 16,2001 now U.S. Pat. No 6,930,661, the entirety of which is incorporatedherein by reference.

BACKGROUND OF THE INVENTION

The present invention relates generally to a bi-directionalcommunication system having a base apparatus and a display apparatus,such as a television receiver.

A remote control (remote commander) is commonly used to adjust thevolume, change the channel, adjust picture quality, or set a timer on atelevision receiver. Operation of the remote control commonly providesfor menus to be displayed on the television screen. These menus displaycertain operations which can be selected and executed via the remotecontrol. Thus, the remote control allows the user to perform variousviewing related operations in accordance with the information displayedin the menus.

Similarly, set-top boxes (STBs) or integrated receiver decoders (IRDs)for receiving satellite broadcasting signals can also be operated byremote control. In addition to the menus commonly found in televisions,STBs generally display an electronic program guide (EPG) on thetelevision screen. Using the remote control, a viewer can select desiredprograms from those shown in the EPG. In this manner, a television or aset-top box which receives a television broadcast signal is designed toutilize a combination of information displays (i.e. menus) operated by aremote control to select and execute various viewing operations.

However, this process of selecting operations from a displayed menuusing a remote control, requires the appropriate information bedisplayed. Further, this sometimes requires a complicated series ofsteps using the remote control. For example, some operations require theuser to navigate a complex hierarchy of menus before finding the desiredoperation, or an operation may require certain inputs that are notconveniently performed using a remote control (e.g., cursor movement ortext input).

SUMMARY OF THE INVENTION

Recent advancements in liquid crystal displays (LCDs) now allow for theproduction of lighter and smaller television displays. Handheldtelevision monitors can now be practically manufactured. A remotecontrol is no longer necessary if the entire device can be convenientlycarried. For such devices, the use of a remote control may actuallycomplicate use of the device.

It is therefore an object of the present invention to provide abi-directional communication system having a display apparatus and abase apparatus which allows for remotely controlled operation and canreadily be used to form a household network.

Other objects and advantages of the invention will in part be obviousand will in part be apparent from the specification and the drawings.

The preferred embodiment of the invention provides a bi-directionalcommunication system having a display apparatus and a base apparatus.The display apparatus has an information signal receiver for wirelesslyreceiving an information signal. A display screen on the displayapparatus displays a video corresponding to the received informationsignal. The display screen is preferably a liquid crystal display. Anoperation display—comprising a plurality of display items correspondingto user selectable operations—is displayed on the display screen.Preferably, the operation display is translucent and is superimposed onthe display screen. A touch screen is provided on the display screen fordetecting a location at which the user touches the display screen. Anoperation signal is then generated corresponding to the item displayedat the position touched on the display screen. An operation signaltransmitter wirelessly transmits the generated operation signal to thebase apparatus. The base apparatus has an information signal transmitterfor wirelessly transmitting the information signal to the displayapparatus and an operation signal receiver for wirelessly receiving theoperation signal from the display apparatus. A control signal isgenerated when a received operation signal corresponds to an operationof an external input apparatus. The external input apparatus can, forexample, be a set-top box, a video tape recorder, a digital versatiledisk apparatus, or the like. An infrared transmitter transmits thecontrol signal to the external input apparatus, which then executes theoperation. The control signal transmitted to the external inputapparatus is generally the same as an infrared signal from a remotecontrol for the external input apparatus.

The base apparatus can also be connected to a plurality of externalinput apparatus. Each external input apparatus can be a source for theinformation signal and the control signals corresponding to operationsof each external input apparatus. The operation display sequentiallydisplays operation displays corresponding to each external inputapparatus when the touched position is outside a currently displayedoperation display.

The base apparatus may include a broadcast signal receiver for receivingbroadcast signals and a channel selector for selecting a channel of thereceived broadcast signals in response to the operation signal. Theinformation signal transmitter then transmits the selected channel asthe information signal to the display apparatus when the operationsignal is an instruction for transmitting the selected channel.

The base apparatus may also include a communication line connection fortransmitting and receiving communication signals. The base apparatusthen transmits received communication signals as the information signalto the display apparatus. The base apparatus can also transmittransmission information through the communication line when theoperation signal from the display apparatus contains transmissioninformation for transmittal to another party connected to thecommunication line.

A second embodiment of the invention is a display apparatus for use in abi-directional communication system. The display apparatus has aninformation signal receiver for wirelessly receiving an informationsignal from a base apparatus. A display screen on the display apparatusdisplays a video corresponding to the received information signal. Thedisplay screen is preferably a liquid crystal display. An operationdisplay—comprising a plurality of display items corresponding to userselectable operations—is displayed on the display screen. Preferably,the operation display is translucent and is superimposed on the displayscreen. A touch screen is provided on the display screen for detecting alocation at which the user touches the display screen. An operationsignal is then generated corresponding to the item displayed at thetouched position on the display screen. An operation signal transmitterwirelessly transmits the generated operation signal to the baseapparatus.

A third embodiment of the invention is a base apparatus for use in abi-directional communication system. The base apparatus has aninformation signal transmitter for wirelessly transmitting aninformation signal to a display apparatus and an operation signalreceiver for wirelessly receiving the operation signal from the displayapparatus. A control signal is generated when a received operationsignal corresponds to an operation of an external input apparatus. Theexternal input apparatus can, for example, be a set-top box, a videotape recorder, a digital versatile disk apparatus, or the like. Aninfrared transmitter transmits the control signal to the external inputapparatus, which then executes the operation. The control signaltransmitted to the external input apparatus is generally the same as aninfrared signal from a remote control for the external input apparatus.

A fourth embodiment of the invention is a method for a bi-directionalcommunication system including a display apparatus and a base apparatus.The method wirelessly transmits an information signal from the baseapparatus to the display apparatus which wirelessly receives theinformation signal. A video corresponding to the information signal isthen displayed on a display screen of the display apparatus. Anoperation display is displayed on the display screen. The operationdisplay comprises a plurality of display items corresponding to userselectable operations. Preferably, the operation display is translucentand is superimposed on the display screen. A touched positioncorresponding to a location on a touch screen on the display screen isdetected. An operation signal corresponding to the display itemdisplayed at the touched position on the display screen is generated.This operation signal is wirelessly transmitted from the displayapparatus to the base apparatus. A control signal is generated when theoperation signal corresponds to an operation of an external inputapparatus. The control signal is transmitted as, for example, aninfrared signal from the base apparatus to the external input apparatuswhich executes the operation. The control signal transmitted to theexternal input apparatus is generally the same as an infrared signalfrom a remote control for the external input apparatus.

Another aspect of the invention is that the method may include abroadcast signal receiving step of receiving broadcast signals and achannel selection step of selecting a channel of the received broadcastsignals in response to the operation signal when the operation signal isan instruction for selecting the channel. The information signaltransmission step transmits the selected channel as the informationsignal to the display apparatus when the operation signal is aninstruction for transmitting the selected channel.

Another aspect of the invention is that the method may include acommunication receiving step, by the base apparatus, of receiving acommunication signal through a communication line. The informationsignal transmission step transmits the received communication signal asthe information signal to the display apparatus when the operationsignal is an instruction for transmitting the received communicationsignal. The base apparatus can also transmit transmission informationthrough the communication line when the operation signal from thedisplay apparatus contains transmission information for transmittal toanother party connected to the communication line.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding of the invention, reference is made tothe following description and accompanying drawings, in which:

FIG. 1 is a system diagram showing a bi-directional communication systemto which the present invention is applied;

FIG. 2 is a block diagram showing a display apparatus to which thepresent invention is applied;

FIG. 3 is a block diagram showing a base apparatus to which the presentinvention is applied;

FIG. 4 is a block diagram showing a set-top box serving as an externalinput apparatus for the bi-directional communication system shown inFIG. 1;

FIG. 5 is a flow chart illustrating the operation of a control paneldisplayed by the display apparatus shown in FIG. 2;

FIG. 6 is a flow chart illustrating the operation of the base apparatusshown in FIG. 3 when an operation signal is received from the displayapparatus shown in FIG. 2;

FIG. 7 is a flow chart illustrating the operation of the set-top boxshown in FIG. 4 when a remote control signal is received from the baseapparatus shown in FIG. 3;

FIG. 8 is a system diagram showing a plurality of external inputapparatuses connected to the base apparatus shown in FIG. 3; and

FIGS. 9A, 9B and 9C are illustrations showing exemplary control panelsdisplayed by the display apparatus for controlling various externalinput apparatuses connected to the base apparatus shown in FIG. 3.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

The preferred embodiments of the apparatus and method according to thepresent invention will be described with reference to the accompanyingdrawings.

Referring to FIG. 1, a bi-directional communication system to which thepresent invention is applied is shown. The bi-directional communicationsystem uses a bi-directional communication method and includes a displayapparatus 100 a base apparatus (base station) 200, and a set-top box 300serving as an exemplary external input apparatus.

The display apparatus 100 is constructed in accordance with the presentinvention and includes an LCD 107 as a display. The display apparatus100 does not require physical connection to the base apparatus 200.Rather the display apparatus communicates with the base apparatus byradio communication. In this manner, the display apparatus can receivean information signal from the base apparatus 200 and transmit a controlsignal to the base apparatus 200.

The base apparatus 200 has an antenna 201 and a tuner for receiving andselecting analog television broadcast signals. The base apparatus 200further includes a modem and a connection terminal (modulator jack) MJfor connecting to a telephone line L. Thus, the base apparatus can beconnected to a telephone network or the Internet.

The base apparatus 200 further has one or more external input terminalsso that various external input apparatus, such as a video tape recorderVTR), a set-top box, an integrated receiver decoder and/or a digitalvideo disk (DVD) apparatus, can be connected to the base apparatus 200.In the arrangement shown in FIG. 1, the set-top box 300 is an externalinput apparatus connected through the external input terminal to thebase apparatus 200.

The base apparatus 200 can compress data, such as a video signal and/oran audio signal from a television program, a communication network,and/or a satellite broadcast received by the set-top box 300. Thecompressed data is formed into a transmission signal and transmitted tothe display apparatus 100.

The display apparatus 100 receives and demodulates the transmissionsignal from the base apparatus 200, extracts a video signal from thedemodulated transmission signal and displays the video signal on the LCD107. Further, the display apparatus 100 extracts an audio signal fromthe demodulated transmission signal and outputs the audio signal to aspeaker (not shown).

The display apparatus 100 can display, on the LCD 107 thereof, the imageof a control panel CP containing operating information and capable ofaccepting an operation input for controlling, for example, the set-topbox 300. As shown in FIG. 1, a control panel image CP is provided forthe set-top box 300 and includes a power supply on/off key, a numerickeypad for channel selection, channel up/down keys, and volume up/downkeys.

The control panel CP is displayed in accordance with software executedby a control section of the display apparatus 100. As hereinafterdescribed, a touch panel 121 is adhered to the LCD 107 to acceptoperation inputs from a user through the displayed control panel image.

The touch panel 121 of the display apparatus 100 can detect a coordinateposition at which the LCD 107 is touched by a finger of the user or thelike. The control section of the display apparatus 100 determines theoperation key displayed on the control panel image CP at the touchedposition, forms an operation signal corresponding to the operation key,and wirelessly transmits the operation signal to the base apparatus 200.

A remote control signal transmitter 250, also referred to as a remotecontrol mouse or the like, which transmits infrared remote controlsignals, is connected to the base apparatus 200. The remote controlsignal transmitter 250 forms a remote control signal in response to anoperation signal from the display apparatus 100 and transmits the remotecontrol signal to the set-top box 300.

The set-top box 300 has a remote control signal reception section 332(formed from a photodetector) for receiving infrared remote controlsignals from a remote control. Thus, the set-top box 300 can receive aremote control signal from the remote control signal transmitter 250connected to the base apparatus 200 and perform operations in accordancewith the received remote control signal. For example, the remote controlsignal transmitter 250 can be used to switch the power on/off or tochange the channel on the set-top box 300. Accordingly, the user canperform set-top box operations by using the control panel CP displayedon the LCD 107 of the display apparatus 100 and the touch panel 121. Inthis manner, the display apparatus 100 and the base apparatus 200communicate bi-directionally, as do the base apparatus 200 and theset-top box 300, the latter functioning as an external input apparatus.

Because, the display apparatus 100 is small in size, light in weight,and connected to the base apparatus 200 only through radiocommunication, the display apparatus 100 can be easily carried.Consequently, a user can carry the display apparatus 100 anywhere withinthe range with which the display apparatus 100 can communicate with thebase apparatus 200.

Accordingly, as described hereinabove, the user can use the displayapparatus 100 to enjoy a television broadcast selected by the tuner ofthe base apparatus 200, enjoy a satellite broadcast selected by theset-top box 300, view a movie when a VTR or a DVD apparatus is connectedas an external input apparatus to the base apparatus 200, and the like.

In addition, the user can use the display apparatus 100 to view awebsite on the Internet through the modem of the base apparatus 200, andreceive and transmit electronic mail (e-mail). When preparing an e-mail,the user can display a software keyboard including, for example,alphabetical keys or symbol keys on the LCD 107 and prepare the e-mailthrough the software keyboard and the touch panel 121. The e-mail isthen sent by operating a transmit key, also displayed on the controlpanel, which sends the e-mail to the base apparatus 200 for transmissionacross the telephone line.

In this manner, the base apparatus 200 serves as a link between thedisplay apparatus 100 and external input apparatus such as the set-topbox 300, information transmission media such as a ground wave televisionbroadcast (cable television), and communication networks such as theInternet. Thus, the display apparatus 100 receives an information signalfrom the base apparatus 200 for display to the user, and formstransmission information, such as e-mails, and transmits thetransmission information through the base apparatus 200.

Referring to FIG. 2, the components of the display apparatus 100 aredescribed. The display apparatus 100 includes a transmission/receptionantenna 101, an antenna multicoupler 102, a reception processing section103, a decoding section 104, an on-screen display (OSD) processingsection 105, a video signal processing section 106, an LCD 107, an audiosignal amplification section 108, a speaker 109, a transmission signalformation section 111, a transmission processing section 112, a touchpanel 121, and a coordinate detection section 122. The components of thedisplay apparatus 100 are controlled by a control section 130. Thecontrol section 130 may be a microcomputer including a centralprocessing unit (CPU) 131, a read only memory (ROM) 132, a random accessmemory (RAM) 133, and an electrically erasable programmable read onlymemory (EEPROM) 134, that are connected to each other by a bus 135. TheROM 132 stores various processing programs to be executed by the displayapparatus 100, predetermined display data for the control panelscorresponding to the connected external input apparatuses (e.g., STB,VTR, DVD) as shown in FIGS. 9A–9C, and command data for the currentmodels of input apparatuses from each manufacturer. When a user connectsan external input apparatus to the base apparatus, the user selects themodel from a list of current models stored in ROM 132 so that thecorresponding control panel can be properly displayed on the displayapparatus. The RAM 133 is used principally as a working area for variousprocesses for temporarily storing data and other necessary information.The EEPROM 134 is a nonvolatile memory and maintains its storedinformation even if the power supply is disconnected. Thus, for example,the EEPROM 134 can store various setting parameters, a homepage on theInternet acquired through the base apparatus 200, an electronic mailprepared to be transmitted through the base apparatus 200 or a receivedelectronic mail, as hereinafter described.

First, operation of the display apparatus 100 when receiving a radiosignal from the base apparatus 200 is described. In the presentembodiment, a predetermined communication protocol such as the IEEE(Institute Electrical and Electronics Engineers) 802.11 system or asimilar protocol is used to effect radio communication between thedisplay apparatus 100 and the base apparatus 200. A radio signal fromthe base apparatus 200 which conforms with the predetermined protocol isreceived by the transmission/reception antenna 101 of the displayapparatus 100 and supplied to the reception processing section 103through the antenna multicoupler 102. The multicoupler 102 is providedto prevent potential interference between a transmission signal and areception signal. The multicoupler 102 prevents a transmission signalfrom the transmission processing section 112 from interfering with asignal received by the transmission/reception antenna 101. Thus, thedisplay apparatus, 100 can receive signals from the base apparatus 200through the transmission/reception antenna 101 and can transmitoperation signals through the antenna, as described hereinafter.

The reception processing section 103 performs required processing,including demodulation of a received signal, and supplies thedemodulated signal to the decoding section (decompression processingsection) 104. As described previously, the base apparatus 200 cancompress data into an information signal from various sources, forexample, a video signal and/or an audio signal of a television broadcastprogram selected by the base apparatus' tuner, display data such astext, video, and/or audio data received through the modem, or a videosignal and/or audio signal of a satellite broadcast program from theset-top box 300. The base apparatus then transmits the compressed datato the display apparatus 100.

The decoding section 104 of the display apparatus 100 receives thedemodulated signal of compressed data from the reception processingsection 103, demultiplexes the signal into a video signal and an audiosignal, and decompresses the signal to restore the signal to itscondition prior to data compression. The decoding section converts therestored video signal and audio signal from a digital format to form ananalog video signal and an analog audio signal. Then, the decodingsection 104 supplies the analog video signal to the on-screen displayprocessing section 105 and supplies the analog audio signal to the audiosignal amplification section 108.

The on-screen display processing section 105 is a text/graphicprocessing circuit for performing video signal processing that allowsthe control panel CP and various messages to be displayed in accordancewith data supplied thereto from the control section 130. This sectionalso allows display information such as characters, pictures and symbolsto be displayed in addition to video of a broadcast program. Forexample, when a control panel is to be displayed in response to aviewer's instruction, information for displaying the control panel issupplied from the control section 130 to the on-screen displayprocessing section 105. Then, the control panel is synthesized with thevideo signal from the decoding section 104 by the on-screen displayprocessing section 105, and the resulting signal is supplied to thevideo signal processing section 106.

For example, when character information indicating channel selections ora volume bar indicating the volume level is to be displayed, informationfor the same is supplied from the control section 130 to the on-screendisplay processing section 105. Then, the control panel is synthesizedwith the video signal from the decoding section 104, and the resultingsignal is supplied to the video signal processing section 106. When acontrol panel CP is not going to be displayed, the on-screen displayprocessing section 105 simply supplies the analog video signal from thedecoding section 104 to the LCD 107. The video signal processing section106 forms a display signal from the video signal and supplies thedisplay signal to the LCD 107.

In this manner, video information corresponding to the video signaltransmitted by radio from the base apparatus 200 is displayed on thedisplay screen of the LCD 107. If display information, such as a controlpanel or the like, is synthesized by the on-screen display processingsection 105, then the display information is displayed along with thevideo information.

Meanwhile, the audio signal amplification section 108 amplifies theaudio signal supplied thereto to a predetermined level and supplies theresulting audio signal to the speaker 109. Consequently, soundcorresponding to the audio signal transmitted by radio from the baseapparatus 200 is output from the speaker 109. Thus, the displayapparatus 100 can receive a video signal and/or an audio signal of atelevision broadcast program transmitted by radio from the baseapparatus 200 and playback and output the received video signal and/oraudio signal to a viewer.

The operation of the display apparatus 100 when displaying a controlpanel on the LCD 107 and accepting an operation input from the user andtransmitting an operation signal corresponding to the operation input tothe base apparatus 200 is now described. The following describes thesituation wherein the display apparatus 100 displays a control panel CPfor controlling the set-top box 300 as shown in FIG. 1 and accepts anoperation input from the user destined for the set-top box 300.

As described hereinabove, the touch panel 121 is adhered to the LCD 107of the display apparatus 100. If the user touches the touch panel 121with his/her finger or the like while the display apparatus 100 ispowered, but when no control panel is being displayed, then thecoordinate detection section 122 detects the touched position(coordinate position) on the touch panel 121 and notifies the controlsection 130 of this touched position. When the control section 130receives notification of a touched position when no control panel isbeing displayed, it interprets the touch as signifying an instruction todisplay a control panel. Thus, upon receipt of the notification from thecoordinate detection section 122, the control section 130 first readsout information necessary for displaying the control panel CP for theset-top box 300 from the ROM 132, forms the information needed todisplay the control panel CP, and supplies the information to theon-screen display processing section 105. The on-screen displayprocessing section 105 receives the information from the control section130, forms a video signal to display the control panel CP, synthesizesthis video signal with an analog video signal from the decoding section104 and displays the control panel CP on the display screen of the LCD107 as shown in FIG. 1.

In the present embodiment, in order to prevent the control panel fromcovering up the video displayed on the LCD 107, the control section 130uses an alpha blending technique to include an alpha value (α value)representing a degree of transparency (translucence) for the controlpanel CP and a color designation for the control panel. This controlpanel color and transparency information is supplied to the on-screendisplay processing section 105. Consequently, the control panel CP isdisplayed on the LCD 107 without completely covering the video. As shownin FIG. 1 the control panel CP is displayed so that a mountain in thevideo signal can be seen through the control panel.

Once a control panel is displayed, if the user touches a position on thetouch panel 121, corresponding to the position of an object operationkey of the control panel CP, then the touched position is detected bythe coordinate detection section 122 and conveyed to the control section130. The control section 130 identifies which operation key was touchedand forms and supplies an operation signal corresponding to theoperation key to the transmission signal formation section 111. Thetransmission signal formation section 111 forms a transmission signal tobe transmitted to the base apparatus 200 based on the operation signaland supplies the transmission signal to the transmission processingsection 112. The transmission processing section 112 processes thetransmission signal supplied thereto for transmission such as modulationand amplification to form a transmission signal of a format to betransmitted and transmits the transmission signal by radio through themulticoupler 102 and the transmission/reception antenna 101 to the baseapparatus 200.

The operation signal transmitted by radio from the display apparatus 100in this manner is received by the base apparatus 200. In the presentexample, the base apparatus 200 then forms a remote control signal forthe set-top box 300 in response to the operation signal from the displayapparatus 100 and transmits the remote control signal so that theset-top box 300 may be remotely controlled.

A key inputting section 141 is connected to the display apparatus 100through an interface (denoted by I/F in FIG. 2) 140. The key inputtingsection 141 includes, for example, a power supply on/off switch. Anoperation input to the key inputting section 141 is supplied through theinterface 140 to the control section 130 for processing in accordancewith the operation key (e.g., connection of the power supply).

In the above description, an operation signal for the set-top box 300 istransmitted through the control panel CP to the set-top box 300.However, the base apparatus 200 can also be remotely controlled by thedisplay apparatus 100. In particular, to remotely control the baseapparatus 200, a control panel for the base apparatus 200 is displayed.As before, if the touch panel 121 is touched while the display ispowered and no control panel is being displayed, then the control panelCP for the set-top box 300 is first displayed as described hereinabove.Then, if the user touches the touch panel 121 in an area other than thearea of the control panel CP, the control section 130 determines thatthis is an instruction to display a control panel for the base apparatus200. The control section 130 can then accept an operation input for thebase apparatus 200 and transmit an operation signal corresponding to theoperation input to the base apparatus 200. The base apparatus 200 thendiscriminates whether the operation signal from the display apparatus100 is for itself or for an external input apparatus, such as theset-top box, 300. If the operation signal is for an external inputapparatus, then the base apparatus 200 transmits the operation signal tothe external input apparatus as described hereinabove. On the otherhand, if the operation signal from the display apparatus 100 is for thebase apparatus 200 itself, the base apparatus 200 controls itself inaccordance with the operation signal. Note that the control panel forthe base apparatus 200 may include a numeric keypad (1 to 12) forselecting channels of the tuner 202, channel up/down keys, and volumeup/down keys. The base apparatus control panel may further include achangeover key for changing whether the base apparatus 200 should outputa signal corresponding to a television broadcast, information receivedthrough the modem, or information from an external input apparatusconnected to the base apparatus. Thus, the control panel for the baseapparatus 200 can be used to remotely control power, channel selection,and changeover of a signal source.

Referring to FIG. 3, the base apparatus 200 shown in FIG. 1 will now bedescribed in detail. The base apparatus 200 includes a tuner 202connected to a reception antenna 201 for receiving analog televisionbroadcast signals, a demodulation section 203, an input terminal 204 fora video signal (Vd), another input terminal 205 for an audio signal(Au), a selector 206, a compression processing section 207, atransmission signal formation section 208, a transmission processingsection 209, an antenna multicoupler 210, a transmission/receptionantenna 211, and a reception processing section 212. The components ofthe base apparatus 200 are controlled by a control section 230. Thecontrol section 230 may be a microcomputer composed of a CPU 231, a ROM232, a RAM 233 and an EEPROM 234 connected to one another by a CPU bus235. The ROM 232 stores various processing programs to be executed bythe base apparatus 200 and data necessary for such processing. The RAM233 is used principally as a working area for various processes fortemporarily storing data and other necessary information. The EEPROM 234is a nonvolatile memory and maintains its stored information even if thepower supply is disconnected. Thus, for example, the EEPROM 234 is usedto realize a last channel memory function of storing the last broadcastchannel received prior to turning the power off, so that when power isturned on again the previous channel is selected.

A modem section 220 is connected to the control section 230. The modemsection 220 includes an interface (I/F) section 221 and a communicationsection 222. The I/F section 221 interfaces a communication line (in thepresent embodiment this is a telephone line) and the base apparatus 200,such that it receives signals transmitted thereto through the telephonecircuit and transmits signals from the base apparatus 200 to thetelephone circuit. The communication section 222 demodulates a signalreceived through the I/F section 221 and supplies the demodulated signalto the control section 230. Further, the communication section 222modulates a transmission signal from the control section 230 andsupplies the modulated transmission signal to the I/F section 221.Consequently, the base apparatus 200 can transmit and receive variousdata to and from an object party through the telephone circuitconnection. Through the modem section 222, the base apparatus 200 can beconnected to the Internet using a telephone line L and an Internetservice provider (ISP) to receive and transmit information (e.g.,electronic mail) through the Internet. To this end, the control section230 controls the modem section 220 to establish an off-hook state or anon-hook state and function as a dialer for the telephone circuit.

The remote control signal transmission section 250 is connected to thecontrol section 230 through a remote control signal formation section241 and an output terminal 242 for the remote control signal. Asdescribed hereinabove, the remote control signal transmission section250 forms a remote control signal in response to an operation signalfrom the display apparatus 100 and transmits the remote control signal.Although not shown in FIG. 3, a key inputting section having a powersupply on/off key and various setting keys is also connected to thecontrol section 230.

Broadcast signals received by the antenna 201 are supplied to the tuner202 of the base apparatus 200, as shown in FIG. 3. The tuner 202 selectsa television broadcast signal corresponding to a channel instructionsignal from the control section 230 and supplies the selected televisionbroadcast signal to the demodulation section 203. The demodulationsection 203 demodulates the television broadcast signal and supplies thedemodulated signal to the selector 206. A video signal input throughvideo input terminal 204 and an audio signal input through audio inputterminal 205 are supplied to the selector 206 in addition to theinformation from the control section 230. The information supplied fromthe control section 230 to the selector 206 may be, for example, awebsite on the Internet or e-mail.

The selector 206 switchably outputs in response to a switching controlsignal from the control section 230 either the signal from thedemodulation section 203, the signals from the input terminals 204 and205, or the signal from the control section 230. The switching controlsignal is formed by the control section 230 in accordance with theoperation signal transmitted from the display apparatus 100 as describedpreviously. The output signal from the selector 206 is then supplied tothe compression processing section 207. The compression processingsection 207 compresses data using a predetermined compression method,for example, MPEG or a wavelet processing method. The signal compressedby the compression processing section 207 is then supplied to thetransmission signal formation section 208. The transmission signalformation section 208 forms a transmission signal in conformity with apredetermined communication protocol. As described hereinabove, the baseapparatus 200 in the present embodiment forms a transmission signal inconformity with, for example, the IEEE (Institute Electrical andElectronics Engineers) 802.11 system. The transmission signal formed bythe transmission signal formation section 208 is supplied to thetransmission processing section 209. The transmission processing section209 performs modulation processing and amplification of the transmissionsignal in accordance with a control signal from the control section 230.The transmission signal processed by the transmission processing section209 is transmitted by radio through the multicoupler 210 and thetransmission/reception antenna 211. The multicoupler 210 is provided toprevent possible interference between a transmission signal and areception signal, similar to the multicoupler 102 of the displayapparatus 100 described previously. In this manner, the base apparatus200 can compress text data, video data and/or audio data of atelevisions broadcast program selected by the tuner 202, a video signaland/or an audio signal accepted through the input terminals 204 and 205,or information acquired through the modem section 220 and transmit thecompressed data by radio in accordance with a predeterminedcommunication protocol to the display apparatus 100.

Operation of the base apparatus 200 when an operation signal istransmitted by radio from the display apparatus 100 is now described. Anoperation signal from the display apparatus 100 received through thetransmission/reception antenna 211 is supplied to the receptionprocessing section 212 through the multicoupler 210. The receptionprocessing section 212 demodulates the signal supplied thereto andfurther performs necessary processing such as A/D (analog/digital)conversion to convert the signal into a signal which can be handled bythe control section 230.

If the signal from the reception processing section 212 is an operationsignal for an external input apparatus, for example the set-top box 300,then the control section 230 supplies the received operation signal tothe remote control signal formation section 241 which forms a remotecontrol signal corresponding to the received operation signal. Theremote control signal formation section 241 supplies the remote controlsignal through the output terminal 242 to the remote control signaltransmission section 250. The remote control signal transmission section250 then transmits the remote control signal as an infraredtransmission. In this manner, the operation for the set-top box 300 issent as an infrared remote control signal to the set-top box 300.

If the signal from the reception processing section 212 is an operationsignal for the base apparatus 200 itself, then the control section 230controls the pertaining components of the base apparatus 200 inaccordance with the received operation signal. Consequently, it isimpossible to change the channel selected by the tuner 202 or changeover the signal output from the selector 206.

On the other hand, if the signal from the reception processing section212 is an acquisition request for a website or a reception/transmissionrequest for electronic mail then the control section 230 controls themodem section 220 to establish a connection to the subscribed ISP,thereby connecting the base apparatus 200 to the Internet. Consequently,the base apparatus 200 can acquire information from a website, andreceive or transmit electronic mail.

In this manner, the base apparatus 200 can receive, select anddemodulate a television broadcast signal, receive and demodulate a videosignal and/or an audio signal from an external input apparatus suppliedthrough the input terminals 204 and 205, or video data and/or audio datasupplied through the modem section 220 and the telephone circuit; thencompress the demodulated video data and/or audio data and transmit thecompressed video data and/or audio data by radio in accordance with apredetermined communication protocol. Further, the base apparatus 200 inthe present embodiment can receive an operation signal transmittedthereto by radio from the display apparatus 100 and control the baseapparatus 200 in accordance with the operation signal, form and transmita remote control signal for controlling an external input apparatus ortransmit information received by radio from the display apparatus 100through the modem section 220.

FIG. 4 is a block diagram showing the set-top box 300 connected as anexternal input apparatus to the base apparatus 200. The set-top box 300includes a digital tuner 302 connected to an antenna 301 for receivingsatellite broadcasts, a descramble section 303, a demultiplexer 304, adecoding section 305 having a video signal decoder and an audio signaldecoder, an on-screen display (OSD) processing section 306, an outputterminal 307 for a video signal (Vd), and an output terminal 308 for anaudio signal (Au). The set-top box 300 further includes a controlsection 310, a key interface (key I/F) 321, a key input section 322, aremote control interface (remote control I/F) 331 and a remote controlsignal reception section 332. The control section 310 is a microcomputercomprised of a CPU 311, a ROM 312, a RAM 313, and an EEPROM 314connected by a CPU bus 315 and which controls the components of theset-top box 300. The ROM 312 stores various processing programs to beexecuted by the set-top box 300 and data necessary for such processing.The RAM 313 is used principally as a working area for temporarilystoring intermediate results from the processing. The EEPROM 314 is anonvolatile memory and maintains its stored information even if thepower supply is disconnected. Hence, the EEPROM 234 is used to storevarious parameter information set by the user. The key input section 322includes a power on/off key and various adjustment keys. If an operationinput from the user is accepted by the key input section 322, then theoperation input is supplied through the key I/F 321 to the controlsection 310 for execution.

The remote control signal reception section 332 can receive a remotecontrol signal of infrared rays from the remote controller for theset-top box 300, convert the remote control signal into an electricsignal and supply the electric signal to the control section 310 throughthe remote control I/F 331. In other words the set-top box 300 can beremotely controlled through the remote controller. Moreover, the remotecontrol signal reception section 332 can receive signals not only fromthe remote controller for the set-top box 300, but also from the remotecontrol signal transmission section 250 of the base apparatus 200.Consequently, remote control of the set-top box 300 can be performed inaccordance with the remote control signal of infrared rays transmittedfrom the base apparatus 200 in response to the operation signal from thedisplay apparatus 100.

When the set-top box 300 is on, it receives digital satellite broadcastsignals and outputs a video signal and an audio signal of a selectedchannel. Note that digital broadcast signals are broadcast in the formof a transport stream (TS) of the MPEG system. Each satellite broadcastsignal includes packetized and time division multiplexed signals anddata including a video signal and an audio signal for a plurality ofbroadcast programs, data used for channel selection, and data fordisplaying an EPG (electronic program guide). Digital satellitebroadcast signals in the form of a transport stream are received by areception antenna 301 located outdoors and are supplied to the tuner302. The tuner 302 selects and demodulates one of the satellitebroadcast signals in accordance with a channel selection control signalsent by the control section 310, and supplies the demodulated broadcastsignal to the descramble section 303. The channel selection controlsignal is formed by the control section 310 in accordance with a remotecontrol signal from the user of the display apparatus 100 which has beenreceived through the remote control signal reception section 332.

The descramble section 303 receives, for example, key information fordecoding or deciphering signals from the control section 310, anddeciphers (cancels) the scrambled (encoded or enciphered) data, andsupplies the descrambled satellite broadcast signal to the demultiplexer304. As described above, the satellite broadcast signal is in the formof a transport stream of packetized and time division multiplexed dataincluding video data and audio data for a plurality of broadcastprograms, digital data regarding the broadcasts, and digital data usedfor formation of an electronic program guide. This format allows asingle satellite broadcast signal to provide a plurality of programs andinformation. Each packet of the satellite broadcast signal has a PID(packet identifier) added thereto such that the set-top box 300 canseparate and extract an object packet from the satellite broadcastsignal. The demultiplexer 304 extracts video data and audio data of aprogram broadcast on the channel selected by the user and supplies theextracted data to the decoding section 305. Further, the demultiplexer304 extracts various data regarding the broadcast and data for formingan electronic program guide from the satellite broadcast signal andsupplies the extracted data to the control section 310. The dataextracted from the satellite broadcast signal and supplied to thecontrol section 310 in this manner is used to select an object programor to form an electronic program guide in accordance with an instructionfrom the user.

The elementary stream (ES) of the broadcast program, (i.e. the videodata and the audio data of the program) is data compressed in accordancewith a coding method of the MPEG system. Therefore, the video signaldecoder of the decoding section 305 expands (decompresses) the videodata to restore the signal prior to data compression then converts thedecompressed digital video signal to obtain an analog signal andsupplies the analog video signal to the on-screen display processingsection 306.

The on-screen display processing section 306 of the set-top box 300 is atext/graphic processing circuit which performs video signal processingto allow various messages or an electronic program guide to bedisplayed. Thus, display information of characters, pictures, symbols,and so forth may be displayed, similarly to the on-screen displayprocessing section 105 of the display apparatus 100.

Accordingly, the on-screen display processing section 306 synthesizesmessage information with the video signal or forms a video signal to beused to display an electronic program guide and outputs this synthesizedor formed signal. Note that if an instruction to synthesize messageinformation or to display an electronic program guide is not received bythe set-top box 300, then the video signal from the decoding section 305is output through the on-screen display processing section 306 to theoutput terminal 307. The video signal output from the set-top box 300 isthen supplied to the base apparatus 200 through the input terminal 204of the base apparatus 200 as described hereinabove.

Meanwhile, the audio signal decoder of the decoding section 305decompresses the audio data to restore the signal prior to datacompression then converts the decompressed digital signal into an analogsignal and outputs the analog audio signal through the output terminal308. The audio signal output from the set-top box 300 is supplied to thebase apparatus 200 through the input terminal 205 of the base apparatus200 similarly to the video signal.

As described above, a remote control signal of infrared rays transmittedto the set-top box 300 from the remote control signal transmissionsection 250 of the base apparatus 200 is received by the remote controlsignal reception section 332. Then, the remote control signal isconverted into an electric signal by the remote control signal receptionsection 332, and the electric signal is supplied to the control section310. The remote control signal may include an instruction for turningthe set-top box 300 on or off, a channel changing instructions orcontrol the demultiplexer 304 to change the program data to beextracted.

In the bidirectional communication system which includes the displayapparatus 100, base apparatus 200 and set-top box 300 described above,the base apparatus 200 transmits a video signal and an audio signal of atelevision broadcast signal received through the tuner 202, informationreceived through the modem section 220, or a video signal and an audiosignal supplied from an external input apparatus such as the set-top box300. This signal is wirelessly transmitted to the display apparatus 100.The display apparatus 100 receives, plays back and outputs the videosignal and/or the audio signal transmitted from the base apparatus 200.Consequently, the user can enjoy a broadcast program provided by ananalog television broadcast signal, a digital satellite broadcast, orinformation provided through a network such as the Internet. The displayapparatus 100 accepts an operation input from a user through a controlpanel displayed on the LCD 107 and transmits an operation signalcorresponding to the operation input by radio to the base apparatus 200,so as to remotely control the base apparatus 200 or the set-top box 300.

Processing when the set-top box 300 is remotely controlled through acontrol panel displayed on the LCD 107 is now described with referenceto the flow charts shown in FIGS. 5 to 7.

FIG. 5 is a flow chart illustrating the processing executed by thecontrol section 130 of the display apparatus 100 once the displayapparatus 100 is turned on. First, the control section 130 of thedisplay apparatus 100 determines whether or not a touch of the touchpanel 121 by a user has occurred (step S11) and if not waits until atouch is detected. If in step S11, the touch panel 121 is touched, thenthe control section 130 displays the control panel CP for the set-topbox 300 (step S12) and accepts an operation input through the controlpanel CP. Then, the control section 130 of the display apparatus 100determines whether or not a touch of the control panel CP by the useroccurs, that is, whether or not an operation input from the user isaccepted (step S13). If it is determined in step S13 that an operationinput from the user is accepted, then the control section 130 determineswhich operation key of the control panel is displayed at the touchedposition based on a detection output from the coordinate detectionsection 122 (step S14). The control section 130 then forms an operationsignal corresponding to the discriminated operation key and supplies theoperation signal to the transmission signal formation section 111, suchthat a transmission signal is formed by the transmission signalformation section 111 (step S15). Then, the transmission signal istransmitted by radio to the base apparatus 200 through the transmissionprocessing section 112, multicoupler 102 and transmission/receptionantenna 101 (step S16). The processing then returns to step S13 to awaitfurther operation inputs by the user.

On the other hand, if it is determined in step S13 that a touch of thecontrol panel has not occurred, then the control section 130 determineswhether or not an instruction to display another control panel isreceived (step S17). The determination in step S17 is whether or not theuser touches the touch panel 121 in a location outside the displayregion of the control panel. If an instruction to display anothercontrol panel is received, then the control section 130 displays anothercontrol panel. In the present embodiment, a control panel for the baseapparatus 200 (step S18) is displayed next. Thereafter, the processingreturns to step S13 to accept an operation input to the newly displayedcontrol panel.

If an instruction to display another control panel is not received, thenthe control section 130 determines whether or not an instruction toerase the control panel is received (step S19). If an instruction toerase the control panel is received, then the control panel is erasedand the processing returns to step S11. If no instruction is received,the process cycles back to step S13. If the process has cycled back tostep S13 a predetermined number of times (corresponding to a time-outperiod), the control section 130 interprets this period of time as aninstruction to erase the control panel and executes step S20.

In this manner, the display apparatus 100 can display a control panel onthe LCD 107, accept an operation input from the user through the use ofthe touch panel 121 adhered to the display screen of the LCD 107 and thecoordinate detection section 122, form an operation signal correspondingto the accepted operation input and transmit the operation signal to thebase apparatus 200.

The processing by the base apparatus 200, which receives the operationsignal transmitted by radio from the display apparatus 100, is nowdescribed with reference to the flow chart of FIG. 6. This processing,illustrated in FIG. 6, is executed by the control section 230 of thebase apparatus 200 after the base apparatus 200 is turned on. The baseapparatus 200 supervises the output signal of the reception processingsection 212 to determine when an operation signal from the displayapparatus 100 is received (step S21). If no operation signal isreceived, then step S21 is repeated. If an operation signal is received,then the control section 230 of the base apparatus 200 determineswhether the operation signal is intended for the base apparatus 200(step S22). If the operation signal is for the base apparatus 200, thenthe control section 230 executes a process in accordance with thereceived operation signal (step S23). For example, controlling the tuner202 to change the selected broadcast signal or changing the selector206. The control section 230 repeats this process by returning to stepS21. In this manner, the base apparatus 200 can be remotely controlledusing the display apparatus 100.

On the other hand, if the operation signal is not for the base apparatus200, then the control section 230 controls the remote control signalformation section 241 to form a remote control signal in accordance withthe received operation signal from the display apparatus 100 (step S24).This remote control signal is supplied to the remote control signaltransmission section 250 through the output terminal 242 and thentransmitted as an infrared signal to the set-top box 300, as theexternal input apparatus (step S25). Consequently, the set-top box. 300can be remotely controlled through the base apparatus 200 using thedisplay apparatus 100.

The processing of the set-top box 300 which receives a remote controlsignal of infrared rays transmitted from the remote control signaltransmission section 250 of the base apparatus 200 is now described withreference to the flow chart of FIG. 7. The processing illustrated inFIG. 7 is executed by the control section 310 of the set-top box 300.Power is supplied to the set-top box 300 and the last selected channelis selected by the last channel memory function so that a video signaland an audio signal may be output. The control section 310 of theset-top box 300 waits at step S31 until it receives a remote controlsignal for the set-top box 300. When a remote control signal destinedfor the set-top box 300 is received, then the control section 310 formsa control signal in accordance with the remote control signal (step S32)and supplies the control signal to the pertaining components of theset-top box for execution (step S33). In this manner, the displayapparatus 100 can be used to remotely control the base apparatus 200 andthe display apparatus 100 can be used to remotely control the set-topbox 300 through the base apparatus 200.

Note that the present embodiment is described with the set-top box 300being connected to the base apparatus 200. However, the presentinvention is not limited to this specific configuration. As describedhereinabove, various input apparatuses such as a VTR, an integratedreceiver decoder, and/or a DVD apparatus can be connected to the baseapparatus 200 in place of the set-top box 300. Further, the baseapparatus 200 may have a plurality of external input terminals, so thatplural external input apparatuses may be connected to the base apparatus200 as seen in FIG. 8. In this instance, the external input terminalsare connected to the selector 206 of the base apparatus 200 shown inFIG. 3 so that one device can be selected at a time by using theselector 206. When a plurality of external input apparatuses areconnected to the base apparatus 200, control panels corresponding toeach of the external input apparatuses can be selectively displayed onthe display screen of the display apparatus 100. FIGS. 9A to 9Cillustrate example or control panel displays corresponding to aplurality of external input apparatus. More particularly, FIG. 9A showsthe control panel CP for the set-top box 300. As described hereinabove,the control panel CP for the set-top box 300 includes a power supplyon/off key, numeral keys, channel up/down keys and sound volume up/downkeys. Similarly, FIG. 9B shows a control panel CP1 for a VTR. Thecontrol panel CP1 includes a power supply on/off key and various keyscorresponding to operation keys for the VTR including a pause key, afast forward key, a rewind key, a playback key, a stop key and arecording key. FIG. 9C shows a control panel CP2 for a DVD apparatus.The control panel CP2 includes a power supply on/off key and variouskeys corresponding to operation keys for the DVD apparatus including apause key, a fast forward key, a rewind key, a playback key and a stopkey.

In this instance, as seen in FIGS. 1 and 9A to 9C, a control panel isdisplayed in the right portion of the LCD 107 as viewed by the user, andwhen the user repetitively touches the touch panel in an area other thanthe control panel the control panels corresponding to the base apparatus200 and the external input apparatuses are displayed successively andsequentially.

More particularly, the display apparatus 100 displays the control panelssequentially as: 1) the control panel CP for the set-top box→2) thecontrol panel for the base apparatus 200→3) the control panel CP1 forthe VTR 400→4) the control panel CP2 for the DVD apparatus 500→5)erasure of the control panel→1) the control panel for the set-top box300.

In this instance, as described hereinabove, the control panel for thebase apparatus 200 includes a changeover key for operating the selector206 to output a signal from the selected external input apparatus.Thereafter, the control panel for the external input apparatus isdisplayed to remotely control the external input apparatus through thedisplay apparatus 100 and the base apparatus 200. In this manner, thecontrol panel displayed on the LCD 107 along with the touch panel can beused to perform as a remote control. When the external input apparatusis a VTR or a DVD apparatus, the control panel can be used to controloperation of the apparatus such as switching on/off of the power supply,pause, fast forwarding, rewinding, playback, stopping and recording.Remote control of the base apparatus 200 and the external inputapparatus connected to the base apparatus 200 is not limited to thoseoperations described above. For example, if the base apparatus 200and/or the set-top box 300 are configured for bilingual audio operation,then a changeover key between a main audio and a sub audio may beprovided on the control panel. Also, when the external input apparatusis a VTR or a DVD apparatus, a playback speed adjustment key may beprovided on the control panel to adjust the playback speed. In thismanner, various remote control operations can be performed through thecontrol panels by providing operation keys corresponding to functions ofthe apparatus to be controlled.

Further, in order for a plurality of external input apparatus to besmoothly controlled, a number of remote control signal transmissionsections may be connected to the base apparatus 200. These remotecontrol signal transmission sections allow for the remote control signalto be transmitted in the proximity of each of the external inputapparatus.

Also, it is possible to provide an electronic program guide display keyon the control panel CP so that an electronic program guide is formed bythe set-top box 300 and displayed on the LCD 107 of the displayapparatus 100 through the base apparatus 200. Then, when a channel isselected through the electronic program guide, display regionscorresponding to channels of the electronic program guide are sent tothe display apparatus 100. When the user touches a portion of the touchpanel 121 corresponding to a program displayed on the electronic programguide, the display apparatus 100 determines which program was selected.Then, the display apparatus 100 forms a channel selection operationsignal for selecting the selected program and transmits the channelselection operation signal to the set-top box 300 through the baseapparatus 200. Consequently, channel selection can be controlled usingthe electronic program guide.

Although, in the present embodiment, when the user repetitively touchesthe touch panel in an area other than the control panel, control panelscorresponding to the base apparatus 200 and the external input apparatusare displayed successively and sequentially, the control panels need notbe displayed in this manner. For example, changeover icons correspondingto various apparatus, which can be switchably used, may be provided oneach control panel such that a control panel corresponding to an objectapparatus may be displayed by operating the corresponding changeovericons.

Further, the base apparatus 200 is not limited to including just a tuner202 and modem section 220. The base apparatus 200 may also function as aVTR or a DVD apparatus, or may function as a set-top box. The baseapparatus 200 may also be configured to accept a signal from an externalinput apparatus and transmit the signal by radio without having a tuner202 or a modem section 220.

Further, in the embodiment described above, the display apparatus 100and the base apparatus 200 are connected to each other by radiocommunication, and the base apparatus 200 and an external inputapparatus are connected to each other by a cable for transmitting aninformation signal and by infrared remote control signals. However, theconnections between the display apparatus 100 and the base apparatus 200and the connections between the base apparatus 200 and the externalinput apparatus are not limited to the specific examples. For example,the display apparatus 100 and the base apparatus 200 may be connected bya wire, and a remote control signal from the base apparatus 200 to theexternal output apparatus may be transmitted by a wire. Further, aninformation signal and a remote control signal may be transmitted byradio communication between the base apparatus 200 and the externalinput apparatus.

While a preferred embodiment of the present invention has been describedusing specific terms, such description is for illustrative purposesonly, and it is to be understood that changes and variations may be madewithout departing from the spirit or scope of the following claims.

1. A bi-directional communication method for a bi-directionalcommunication system including a display apparatus and a base apparatus,said method comprising the steps of: wirelessly transmitting aninformation signal from a website to said display apparatus; wirelesslyreceiving at said display apparatus the information signal from thewebsite; displaying a video corresponding to said information signal ona display screen of said display apparatus; displaying an operationdisplay on said display screen, said operation display comprising aplurality of display items corresponding to user selectable operationsand a control panel representing a remote control of an external inputapparatus to be connected to the base apparatus; detecting a touchedposition corresponding to a location at which a user touches a touchscreen provided on said display screen; generating an operation signalcorresponding to the display item displayed at the touched position onsaid display screen; wirelessly transmitting said operation signal fromsaid display apparatus to said base apparatus; wirelessly receiving atsaid base apparatus said operation signal from said display apparatus;generating a control signal when said operation signal corresponds to anoperation of an external input apparatus; said control signal being thesame as a signal from said remote control corresponding to saidoperation; receiving at said base apparatus a communication signalthrough a communication line; transmitting the received communicationsignal as the information signal to said display apparatus when theoperation signal is an instruction for transmitting the receivedcommunication signal; transmitting transmission information by said baseapparatus through the communication line when the operation signal fromsaid display apparatus contains said transmission information fortransmittal to an object party connected to said communication line; andtransmitting said control signal from said base apparatus to saidexternal input apparatus; whereby said external input apparatus executessaid operation.